416 



PROTOZOOLOGY 



Fig. 188. The life-cycle of Eimeria schubergi, X400 (Schaudinn). 

 a, entrance of a sporozoite in the gut epithelial cell of host and growth 

 of schizont; b, schizogony; c, macro- and micro-gametocyte; d, e, for- 

 mation of macrogamete; f-h, formation of microgametes; i, mature 

 gametes prior to fusion; j, k, fertilization; 1-n, spore-formation; 

 o, oocyst containing four mature spores, each with two sporozoites; 

 p, germination of spores in host's gut. 



a compact appearance (f-h). The biflagellate comma-shaped mi- 

 crogametes thus produced, show activity when freed from the 

 host cells (i). A microgamete and a macrogamete unite to form a 

 zygote which secretes a membrane around itself (j). This stage is 

 known as the oocyst. The nucleus divides twice and produces four 

 nuclei (k-m). Each of the four nuclei becomes the center of a spo- 

 roblast which secretes a membrane and transforms itself into a 

 spore (n). Its nucleus, in the meantime, undergoes a division, so 

 that the two sporozoites become developed in the spore (o). Thus 

 an oocyst of this species contains four spores and eight sporo- 



